The present invention relates generally to tools for the removal of valve seats and in particular to a valve seat puller useful, for example, in the petroleum industries.
Pumps used for the pumping of fluid used in oil and natural gas extraction operations may include valve seats that wear over time and must be replaced. These valve seats are usually press fit into a casting or the like and must be pulled free from within the casting using considerable force, for example, obtained through a hydraulic cylinder.
Valve seat pullers are known which can extend into a casting and pass through a valve seat to extract the valve seat. The pullers include jaws with outwardly extending teeth for engaging a backside of the valve seat and for providing a shaft which can attach to a hydraulic cylinder to apply the necessary force to the valve seat. Because of the considerable force applied to the valve seat, a method of preventing the jaws from retracting during this process may be required.
U.S. Pat. No. 9,302,380 hereby incorporated by reference describes a valve seat puller where the jaws are pressed outward by a tapered cone attached to the valve puller shaft. When the shaft is pulled upward after the jaws have been fit through a valve seat, the cone shaft urges the jaws outward with a pressure comparable to that required for the extraction.